Electronic discharge device having a wire mesh element to control the electron flow



Oct. 4, 1955 w. MULLER 2,719,935

ELECTRONIC DISCHARGE DEVICE HAVING A WIRE MESH ELEMENT TO CONTROL THE ELECTRON FLOW Filed Jan. 25, 1952 Jivea ur. Werner fiozfer.

United States Patent ELECTRONIC DISCHARGE DEVICE HAVING A WIRE MESH ELEMENT TO CONTROL THE ELECTRON FLOW Werner Miiller, Berlin-Siemensstadt, Germany, assignor to Siemens & Halske Aktiengesellschaft, Munich, Germany, a German corporation Application January 23, 1952, Serial No. 267,870

Claims priority, application Germany February 5, 1951 2 Claims. (Cl. 313-243) This invention relates to electron discharge devices having a tubular wire mesh control grid electrode which is entirely unobstructed throughout its entire tubular extent, as disclosed in the copending application Ser. No. 267,860, filed January 23, 1952, and is particularly conconcerned With the provision, in such structures, of an auxiliary tubular wire mesh grid for reducing and practically inhibiting the bombardment of the wire mesh control grid electrode by the electron stream emitted by the cathode, such auxiliary wire mesh grid being connected at cathode potential or at negative potential and being disposed between the cathode and the tubular wire mesh control grid electrode ahead of the control grid electrode as viewed in the direction of the electron flow.

Details of the invention will appear from the description of an embodiment thereof, which will be rendered with reference to the accompanying drawings. In these drawings,

Fig. 1 shows in diagrammatic partially sectional representation an electrode structure according to the invention; and

Fig. 2 is a diagrammatic sectional view approximately along line 22 of Fig. 1.

Numeral 1 designates the tubular wire mesh control grid electrode formed by the wires 2 arranged crosswise in spiral-like fashion and welded together at the crossing points. A copper cylinder 3 is provided which serves as sole support and carrier for the wire mesh of the control grid 1, such grid extending, as shown in Fig. 1, axially freely from the carrier 3 without any additional support whatever. Suitable terminal means (not shown) may be provided to supply current to the control grid 1 over the carrier member 3. The cathode 4 is a tubular structure disposed concentrically within the wire mesh control grid electrode 1 and carried by a tubular metallic member similar to the carrier 3 and disposed concentrically within said carrier.

The wires 2 of the tubular wire mesh control grid 1 are shown in Fig. 2 in section. Within the space enclosed by the wire mesh control grid electrode is disposed the tubular cathode 4. In order to reduce and practically inhibit the bombardment of the wire mesh of the grid electrode 1 by the electron stream emitted by the cathode 4, there is provided between the cathode 4 and the wires 2 of the wire mesh of the control grid 1 an auxiliary grid 5 which is structurally similar to the grid 1, being likewise formed as a wire mesh grid having the wires 6. As is apparent from Fig. 1, the auxiliary grid 5 (wires 6) is supported solely by a tubular carrier such as the carrier 3 provided for the control grid 1 (wires 2). The wires 6 of the auxiliary electrode 5 are of smaller gage than the wires 2 of the control grid electrode 1 and are thus disposed ahead of the latter, as viewed in the direction of the electron flow emanating from the cathode 4.

The auxiliary grid 5 is by suitable generally known circuit means placed on cathode potential or on negative potential, and the electron bombardment of the wires 2 of the mesh of the control grid 1 is thus practically avoided. The electron flow is through the spaces between the wires 2 of the control grid to the anode 7 of the discharge device.

A discharge device formed in accordance with the in vention reduces the control input as compared with de vices lacking the new wire mesh type auxiliary grid.

The electrode structure described above and diagramatically shown in the drawings is of course disposed in an envelope and suitably mounted therein. The envelope and the mounting means for the electrode structure have been omitted in order to keep the drawings simple.

Changes may be made within the scope and spirit of the appended claims.

I claim:

1. An electron tube comprising a tubular cathode, a tubular wire mesh control electrode surrounding said cathode concentrically therewith and radially spaced therefrom and forming an annular axially extending space therewith, a tubular sheet metal carrier member connected with the wires of said tubular wire mesh control electrode at one end thereof and axially extending therefrom, said carrier member constituting the sole and exclusive support for said tubular wire mesh control electrode which extends axially freely therefrom to the opposite end thereof and also constituting a current supply element for said control electrode over which current may be supplied to the wires thereof which are connected thereto, an anode surrounding said wire mesh control electrode, an auxiliary tubular wire mesh electrode structurally similar to said control electrode and a tubular sheet metal carrier member solely supporting the same and being structurally and functionally similar to the carrier member of said control electrode, said auxiliary tubular wire mesh electrode being disposed within said annular space between said cathode and said tubular wire mesh control electrode concentric therewith and radially spaced from said cathode and said control electrode, the wires of said auxiliary electrode being interposed in the electron path between said cathode and the wires of said control electrode for the purpose of substantially preventing electron bombardment of the wires of said control electrode.

2. An electron tube as set forth in claim 1, wherein the wire diameter of said control electrode exceeds the wire diameter of said auxiliary electrode.

References Cited in the file of this patent UNITED STATES PATENTS 1,736,815 Albersheim Nov. 26, 1929 1,816,682 Langmuir July 28, 1931 1,844,319 Hatt Feb. 9, 1932 1,874,355 Round Aug. 30, 1932 1,991,767 McCullough Feb. 19, 1935 2,228,895 Linder Jan. 14, 1941 

